<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>

<body>
    <div id="app">
        <h1>新闻</h1>
        <ul>
            <!-- 
          需要遍历哪一个元素,就在哪一个元素上使用v-for指令
          遍历可以使用in 也可以使用of
          遍历中item和index会作为`局部变量`在当前被遍历的元素上及内部直接使用

         -->
         <button @click="news.unshift({id:'004',content:'新增'})">add</button>
         <li v-for="item,index of news" :key="item.id">
            <p>编号：{{item.id}}</p>
            <p>{{item.content}}</p>
         </li>
        </ul>
    </div>
    <script>
        Vue.config.productionTip = false;

        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    news:[
                        {id:"001",content:"今天我们......"},
                        {id:"002",content:"明天要下雨....."},
                        {id:"003",content:"后天要放假....."}
                    ]
                }
            }
        })
    </script>
</body>

</html>